Electronic device manufacturers frequently utilize burn-in testing for quality-assurance purposes. Burn-in testing typically entails positioning a device under test (DUT) in a corresponding socket of a test board and then subjecting the DUT to voltages and temperatures in excess of the expected normal operating conditions for extended periods of time. However, without overcurrent protection, the DUT can sink an excessive amount of current, which causes the DUT to melt in the test socket, rendering the socket unusable.
A conventional technique for supplying overcurrent protection is to position a metal fuse between the power supply and the voltage supply input of the DUT. However, the use of metal fuses often introduces additional problems. For one, an operator typically has to manually check each fuse to determine whether it has been blown, thereby incurring significant effort in verifying correct operation of the test board. Another problem with the use of a metal fuse is that it typically incurs a relatively large voltage drop across the fuse terminals during operation, thereby extending the amount of time for the burn-in process due to the reduced voltage applied to the DUT. Further, metal fuses typically are relatively slow to blow during an overcurrent condition. This relatively slow fuse blow time can result in damage to both the DUT and the test socket in the event of an overcurrent condition. Accordingly, an improved technique for overcurrent protection for a DUT would be advantageous.
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